TAS05567, a Novel Potent and Selective Spleen Tyrosine Kinase Inhibitor, Abrogates Immunoglobulin-Mediated Autoimmune and Allergic Reactions in Rodent Models.

Spleen tyrosine kinase (Syk) is involved in regulation of B-cell receptor (BCR) and Fc receptor downstream signal pathways. Syk plays an essential role in production of inflammatory mediators and differentiation in various immune cells and is therefore an attractive target for treating inflammatory conditions, such as autoimmune and allergic diseases. We identified TAS05567 as a highly selective Syk inhibitor and evaluated its therapeutic potential in animal models. In vitro biochemical assays were performed with available kinase assay panels. Inhibitory effects of TAS05567 on immune cells were analyzed by assessing the Syk downstream signaling pathway and production of inflammatory factors. In vivo effects of TAS05567 were evaluated in animal models of autoimmune diseases and antigen-specific IgE transgenic mice. TAS05567 inhibited only 4 of 191 kinases tested but inhibited Syk enzymatic activity with high potency. TAS05567 inhibited BCR-dependent signal transduction in Ramos cells, FcγR-mediated tumor necrosis factor-α production in THP-1 cells, and FcεR-mediated histamine release from RBL-2H3 cells. In rheumatoid arthritis models, TAS05567 suppressed hind-paw swelling in a dose-dependent manner compared with vehicle. Moreover, TAS05667 markedly reduced histopathologic scores in an established rat arthritis model. In a mouse immune thrombocytopenic purpura model, platelet counts were reduced with injection of anti-platelet antibody. TAS05567 prevented the platelet count decrease in a dose-dependent manner. Finally, TAS05567 treatment suppressed IgE-mediated ear swelling in vivo. Collectively, our data indicate TAS05567 is a selective Syk inhibitor and potential therapeutic candidate for treating humoral immune-mediated inflammatory conditions such as autoimmune and allergic diseases.

Five-year follow-up two-dimensional speckle tracking echocardiography in a juvenile with a double-chambered left ventricle.

Double-chambered left ventricle (DCLV) is a particularly rare congenital entity characterized by the presence of two ventricular cavities separated by an abnormal muscle band. An asymptomatic 15-year-old boy was referred to our hospital because of electrocardiographic (ECG) abnormalities. His initial transthoracic echocardiography (TTE) demonstrated a DCLV with mild left ventricular systolic dysfunction. During a 5-year follow-up period, he remained symptom free with no changes in ECG and conventional TTE findings. However, two-dimensional speckle tracking echocardiography revealed a subtle progressive deterioration of left ventricular systolic function during the 5-year follow-up.

RETINAL BLOOD FLOW CORRELATES TO AQUEOUS VASCULAR ENDOTHELIAL GROWTH FACTOR IN CENTRAL RETINAL VEIN OCCLUSION.

PURPOSE: As laser speckle flowgraphy can measure blood flow distribution in the ocular fundus, the authors analyzed the relationship between retinal blood flow and aqueous vascular endothelial growth factor (VEGF) concentration in central retinal vein occlusion. METHODS: This prospective observational study examined 45 eyes of 45 patients with central retinal vein occlusion before treatment. Blood flow in large vessels around and at the optic disk, aqueous VEGF concentration, and arteriovenous passage time were examined. Blood flow was evaluated as mean blur rate by laser speckle flowgraphy. RESULTS: Fluorescein angiography found 20 ischemic and 25 nonischemic type eyes. Aqueous VEGF concentration in the ischemic type was significantly higher than that in the nonischemic type (P = 0.01). Arteriovenous passage time was significantly correlated to the logarithm of the aqueous VEGF concentration (P = 0.0001). Mean blur rate of the affected eye/mean blur rate of the unaffected eye of the ischemic type was significantly lower than the nonischemic type (P = 0.039). Additionally, mean blur rate was significantly correlated both to the logarithm of the aqueous VEGF concentration (P < 0.0001) and to the arteriovenous passage time (P = 0.0001). CONCLUSION: Laser speckle flowgraphy may be useful for predicting aqueous VEGF concentration and severity of central retinal vein occlusion.

Modulation of tumor immune microenvironment by TAS-115, a multi-receptor tyrosine kinase inhibitor, promotes antitumor immunity and contributes anti-PD-1 antibody therapy.

TAS-115 is an oral multi-receptor tyrosine kinase inhibitor that strongly inhibits kinases implicated in antitumor immunity, such as colony stimulating factor 1 receptor and vascular endothelial growth factor receptor. Because these kinases are associated with the modulation of immune pathways, we investigated the immunomodulatory activity of TAS-115. An in vitro cytokine assay revealed that TAS-115 upregulated interferon γ (IFNγ) and interleukin-2 secretion by T cells, suggesting that TAS-115 activated T cells. Gene expression analysis suggested that TAS-115 promoted M1 macrophage differentiation. In in vivo experiments, although TAS-115 exerted a moderate antitumor effect in the MC38 mouse colorectal cancer model under immunodeficient conditions, this effect was enhanced under immunocompetent conditions. Furthermore, combination of TAS-115 and anti-PD-1 antibody exhibited greater antitumor activity than either treatment alone. Flow cytometry analysis showed the increase in IFNγ- and granzyme B (Gzmb)-secreting tumor-infiltrating T cells by TAS-115 treatment. The combination treatment further increased the percentage of Gzmb+CD8+ T cells and decreased the percentage of macrophages compared with either treatment alone. These results highlight the potential therapeutic effect of TAS-115 in combination with PD-1 blockade, mediated via activation of antitumor immunity by TAS-115.

Intravenous nicorandil for treatment of the urgent phase acute heart failure syndromes: A randomized, controlled trial.

BACKGROUND: Vasodilators, such as nitroglycerin, have long been first-line treatments for acute heart failure syndromes (AHFS). Nicorandil is a vasodilator with dual potassium channel opening and nitrate properties. However, there are no randomized controlled studies of intravenous nicorandil safety and efficacy in the urgent phase AHFS. We examined the symptomatic, hemodynamic, and echocardiographic effects and safety, and 60-day clinical outcomes of intravenous nicorandil, in addition to standard therapy, in patients with AHFS in the urgent phase. METHODS: In this prospective, randomized controlled trial, 106 AHFS patients were randomized within one hour of arrival to receive either standard therapy (control group, n=56) or standard therapy plus simultaneous intravenous nicorandil (0.2 mg/kg bolus followed by 0.2 mg/kg/h for 24 h; nicorandil group, n=50). Outcomes were assessed at 60 days. RESULTS: Patients in the nicorandil group exhibited greater improvement of dyspnea as measured by change in a five-point Likert scale compared to those in the control group (after 1 h infusion: p=0.006, 6 h; p<0.001). The nicorandil group also showed significantly improved E/e', an estimate of left ventricular filling pressure, at 1 and 24 h ( p=0.001 and p=0.004, respectively). In addition, intravenous nicorandil therapy was safe and did not cause side effects such as excessive hypotension or reflex tachycardia. However, it did not reduce all-cause mortality and readmission rates at 60 days. CONCLUSIONS: Addition of intravenous nicorandil to standard therapy for urgent phase AHFS improved dyspnea and left ventricular diastolic function but not 60-day outcome.